Method of and apparatus for cutting a moving ribbon of glass



April 5, 1955 P. M. DENLOW METHOD OF AN D APPARATUS FOR CUTTING A MOVINGRIBBON OF GLASS 4 Sheets-Sheet 1 Filed Oct. 9, 195-3 H11HIIHIIIIIIIIIIIIIIH Inventor {6: iltorney;

April 5, 1955 P. M. DEN LOW METHOD OF AND APPA RATUS FOR CUTTING AMOVING RIBBON 0F GLASS Filed Oct. 9, 1953 4 Sheets-Sheet 2 InventorApril 5, 1955 p M, ow 2,705,390

METHQD OF AND APPARATUS FOR CUTTING A MOVING RIBBON 0F GLASS Filed ot.9. 1953 4 She ets-Sheet s Inventor Attorney;

Aprll 5, 1955 P. M. DENLOW 2,705,390 METHOD OF AND APPARATUS FOR CUTTINGA MOVING RIBBON OF GLASS Filed Oct. 9, 1955 4 Sheets-Sheet 4 ln venlorBy v MWAUQM J United States Patent METHOD OF AND APPARATUS FOR CUTTING AMOVING RIBBON OF GLASS Peter M. Denlow, Eccleston, near St. Helens,England, assignor to Pilkington Brothers Limited, Liverpool, England, aBritish company Application October 9, 1953, Serial No. 385,191

6 Claims. (Cl. 4948) This invention relates to a method of and apparatusfor producing glass sheets of predetermined size from a moving ribbon ofglass.

As is well understood in the art, in one method of the manufacture ofsheet glass a continuous ribbon of glass issues from an annealingchamber of a drawing kiln, and during the upward movement of the ribbona horizontally moving scoring device makes an excursion across the widthof the ribbon (e. g. as is described in United Kingdom Patent No.456,822) to form therein during movement in one direction a transversescore line at a predetermined interval from the leading edge accordingto the desired lengths of sheets to be divided from the ribbon.

The intervals of operation of the scoring device are determined by aswitch operated by the leading edge of the ribbon, and the demarkedleading end portion of the ribbon is gripped by suckers (e. g. asdescribed in United States Patent No. 2,628,453) and snapped off alongthe score line. Thereafter each snapped-01f portion is laid flat on atable and longitudinal score lines are manually formed therein alongwhich the glass is snapped to trim off unwanted marginal portions and,if desired, to divide the portion into sections (in sheet form) ofdesired width.

A main object of the present invention is to provide a method of and anapparatus for producing glass sections in sheet form of predetermineddimensions from a moving ribbon of glass whereby the transverse andlongitudinal score lines are formed in the moving ribbon of glass, andso to arrange the score lines that irregular breaking of the glass doesnot occur.

According to the present invention a method of producing glass sectionsin sheet form of predetermined dimensions from a moving ribbon of glassis characterised by defining the width of the sections to be produced byforming longitudinal score lines in spaced relation on one face of themoving ribbon, and interrupting each longitudinal score line for a shortdistance at such a distance from the leading edge of the ribbon that atransverse score line, formed on the other face of the ribbon todetermine the length of a sheet, does not cross the longitudinal scorelines and does not prematurely start division of the ribbon along thelongitudinal score lines in order that a sheet, snapped from the ribbonalong a transverse score line, may be snapped subsequently along thelongitudinal scorelines in the sheet to obtain the glass sections ofpredetermined size.

Further according to the present invention, there is provided inapparatus for vertically drawing fiat glass in ribbon form includingmeans for scoring a line of breakage across the ribbon emerging from theannealing chamber of a drawing kiln at a predetermined distance from theleading edge of the ribbon; retractable cutters for forming longitudinalscore lines in spaced relation on the moving ribbon operativelyassociated with interrupting mechanism, said interrupting mechanismcomprising a settable switch actuated by the leading edge of the ribbon,said settable switch controlling an electrical circuit comprisingactuating means associated with a spring controlled valve to move thelatter to the open position, a piston working in a cylinder suppliedwith motive fluid through said valve, means operatively associated withthe piston and said actuating means for dissociating the actuating meansfor said valve from said valve to permit said valve to return to closedposition, said piston actuating the retractable scoring means to movethem out of operative position, and means for returning the actuatingmeans "ice into association with the valve, and the retractable scoringmeans to operative position when the fluid is cut off from the cylinder.

The invention comprehends a novel method of operation in which the scorelines are so arranged as not to cross each other, as viewed through theglass, and by this arrangement premature breaking at the longitudinalscore lines when the glass is snapped at the transverse score lines isavoided.

In order that the invention may be clearly understood one preferredembodiment thereof as applied to the annealing chamber of a verticaldrawing kiln will now be described, by way of example, with reference tothe accompanying diagrammatic drawings, in which:

Fig. 1 is a diagrammatic side elevation of apparatus according to theinvention,

Fig. 2 illustrates, to a relatively small scale, the manner in whichtransverse and longitudinal scores are formed in a moving glass ribbon.

Fig. 3 illustrates, to the same scale as used in Fig. 2, a leading endportion of the ribbon. after it has been snapped from the ribbon,

Fig. 4 illustrates to the same scale at Fig. 3 the portions shown inFig. 3 after snapping thereof has been effected along the longitudinalscores formed therein to complete the production of glass sections ofpredetermined dimen- SlOIlS.

Fig. 5 is a broken plan of part of the device which makes thelongitudinal score lines,

Fig. 6 is a fragmentary sectional elevation taken on line VI-VI of Fig.5, and

Fig. 7 is a pictorial illustration showing diagrammatically one of thelongitudinal scoring devices and actuating mechanism therefor, thetransverse scoring device being omitted for the sake of clarity.

In the drawings like references indicate the same or similar parts.

Referring to the drawings, a continuous ribbon 1 of glass is drawnupwards through an annealing chamber indicated at 2 of a verticaldrawing kiln (not shown) by a vertical series of pairs of rollers(mounted within the annealing chamber) of which one pair only isindicated at 3, Fig. 1. These rollers 3 are driven in known manner bygears, not shown, from a shaft 4 rotated by a pulley 5 and multiple belt6 from the output shaft of an infinitely variable gear coupled to anelectric motor (not shown).

The ribbon 1 is advanced by the rollers in the annealing chamber at aconstant speed and a transverse score line T, F1g. 2, is formed on oneface thereof at a predetermined interval from the leading edge of theribbon according to the required length of the sheet sections to beseparated in succession from the ribbon, by a transverse scoring device7 mounted on a carriage 8, reciprocable across the ribbon 1 by wirecable 9.

Movement of the carriage 8 may be controlled conveniently in the mannerdescribed in United Kingdom spec fication No. 456,822. Movement of thecarriage 8 is initiated by the closing of a mercury switch 10 adjustab1ymounted on a post 11 for pivotal movement by the leading edge of theadvancing ribbon 1. At the end of a to-and-fro excursion of the carriage8, the carriage is halted until a subsequent actuation by closing of themercury switch 10.

The scoring device 7 acts against the rear face of the Ilbl'JOIl 1,which is supported against the thrust of the device by a roller 12. Thescoring device 7 engages the ribbon only while being moved in onedirection across the ribbon and the transverse score line T, Fig. 2,formed by it does not extend to the longitudinal edges of the ribbon butstops just short thereof. Accordingly the ribbon is not weakened acrossits entire width and this provision ensures that snapping of the glassalong a transverse score line T does not occur prior to the leading endportion of the ribbon reaching a position at which it can be snapped oifunder proper control. This may, in known manner, be effected by atiltingsucker device 13, Fig. 1, which may be of the form described in UnitedStates Patent No. 2,628,453 which is moved into gripping engagement withthe front of the glass and then forwardly tilts the leading end portionof the ribbon so that it snaps along the line T, the snapped-01f portionas illustrated in Fig. 3 being then lowered by the sucker device on to aportable frame or table. The thrust of the suckers 13 against the ribbonis counteracted by means of rollers 14 mounted on arms 15, whoseposition may be adjusted by the levers 16.

Below the transverse scoring device 7, Fig. 1, are provided threeretractable scoring devices 17, the number of such devices depending onthe number of sections in sheet form into which a leading portion of theribbon 1 is to be divided. In Fig. 2 is illustrated a part of a leadingportion of a ribbon intended to be divided into two sections S1, S2,Fig. 4, and the unwanted marginal portion E of the ribbon removedtherefrom. Accordingly three retractable scoring devices 17 forproducing the requisite longitudinal score lines are provided, only oneof which is illustrated in Figs. to 7, and these form three longitudinalscore lines L1, L2, and L3, Fig. 2, in the ribbon, before the leadingportion is demarked by the transverse scoring device 7. As can be seenfrom Fig. l, the scoring devices 17 are located below the device 7 andact against the front face of the ribbon. To prevent the ribbon snappingalong the lines L1, L2 and L3 before such action can be performed underproper control, and also to avoid irregular breaking, the operation ofthe retractable scoring devices 17 is interrupted at predeterminedintervals so that the score lines L1, L2, L3 are each interrupted for ashort distance D, see Fig. 2, at such a distance from the leading edgeof the ribbon 1 that a transverse score line T, as viewed through theglass ribbon, does not cross the longitudinal score lines L1, L2, L3.

Referring now in particular to Figs. 5 and 7 of. the

drawings of which Fig. 7 illustrates diagrammatically one form ofapparatus for interrupting the operation of the retractable scoringdevices 17, each scoring device 17 is carried by an arm 18, supported bya pivot pin 19, Figs. 6 and 7 in a frame 20 on a bracket 21 secured to across bar 22 fixed by bolts 23, Fig. 5, to brackets 24 mounted on themachine frame 25. The bracket 21 is slidable along the cross bar 22 topermit the position of the scoring device 17 to be adjusted relative tothe longitudinal edges of the ribbon 1, and the frame 20 is pivoted at26 to the bracket 21 to permit the frame 20, arm 18 and device 17 to beswung anti-clockwise as viewed in Fig. 6, about the pivot 26 to inactiveposition. The scoring device 17 is maintained in operative engagementwith the ribbon 1 by a spring 27, Fig. 6, which 4,

acts on the arm 18 and is tensioned by an adjusting screw 28. The ribbon1 is supported against the thrust of each scoring device 17 by rollers29, Fig. 1.

Each of the scoring devices 17 is supported by the cross bar 22, as justdescribed, and a bail 30 common to the devices 17 is provided to retractsimultaneously the devices from operative engagement with the ribbon 1,the bail 30 being movable to engage the lower ends of the arms 18 andswing them anti-clockwise, as viewed in Fig. 6. The bail 30 is supportedat its ends by rocking arms 31 pivoted on bolts 32, Fig. 5, carried inthe brackets 24, and connecting rods 33, 34, connect the rocking arms 31with bell-cranks 35, 36 secured to a fixed cross-shaft 37 journaled inbearings 38 supported by a bearer 39 secured to the machine frame 25.The bell-crank carries a pin 40 to which is connected a spring 41.

Operation of the bail 30 is initiated by a second mercury switch 42,Figs. 1 and 7, pivotally supported by the post 11 for engagement by theleading edge of the ribbon 1 at a predetermined distance in advance ofwhich the switch 10 is engaged by the leading edge of the ribbon. Theswitch 42 is so spaced from switch 10 that it initiates operation of thebail 30 to retract the scoring devices 17 from the ribbon at thepredetermined position on the ribbon in advance of that at which theribbon is to be engaged by the transverse scoring device 7, andmechanism about to be described permits the bail to be restored to itsinactive position, clear of the arms 18, after a predetermined intervalof time, this interval being so chosen that by retracting the scoringdevices 17 from the ribbon and then restoring them to operativeengagement therewith the longitudinal score lines L1, L2, L3 formed inthe ribbon are interrupted at a predetermined distance from the leadingedge of the ribbon to provide for a distance D, Fig. 2, the area of theribbon which is not scored longitudinally and across substantially thecentre of which, considered in the direction of movement of the ribbon,the transverse score line T is formed so that it does not cross thelongitudinal score lines L1, L2, L3 as viewed through the ribbon.

The switches 10 and 42 are adjustable lengthwise of the post 11, awing-nut 43, Fig. l, permitting adjustment of the switches roughly todetermine the position at which switch 10 will be engaged by the leadingedge of the ribbon 1 and adjusting screws 44, 45 permitting respectivelyfine adjustment of the height of switch 10 and adjustment of switch 42relative to switch 10.

Referring to Fig. 7, the switch 42 is included in an electric circuitsupplied with current through a manually operated switch 46. When themercury switch 42 is actuated by the leading edge of the ribbon 1 itcauses a contactor 47 to be closed so that current passes to andenergises the coil of a solenoid 48. The solenoid 48 is provided with anarmature 49 having a forked end carrying a pivot pin 50 from whichdepends a latch 51 having formed therein a latching notch 52 whichnormally engages one end of a lever 53 pivoted at 54, the other end ofthe lever engaging a spring-controlled plunger 55 of an air valve 56.

The inlet side of the air valve 56 is connected by piping 57 with asource, not shown, of compressed air and the outlet side of the valve isconnected by piping 58 through a device 59 of known construction whichpermits air to pass freely to a cylinder 60 but obstructs air passing inthe opposite direction, the degree of obstruction being controlled by anaxially displaceable regulator 61. In the cylinder 60 works a piston 62from which depends a piston rod 63 having at its lower end a fork 64 bywhich it is connected to the pin 40 carried by the bell-crank 35. Thevalve 56 is normally in the closed position.

The piping 57 on the inlet side of the air valve 56 includes a shut-offvalve 65 by which air from a compressor, not shown, can be admitted toor excluded from the piping, a pressure reducing valve 66, and anair-line oiling point 67.

In operation, the switch 46 is closed, as shown in Fig. 7, and onactuation of the mercury switch 42 by the leading edge of the ribbon 1,the contactor 47 places the solenoid 48 in circuit and its armature 49is actuated so that the latch 51 is drawn upwards, thus rocking thelever 53 to release the air valve 56 and permit the passage of air underpressure into the cylinder 60. The air entering the cylinder causes thepiston 62 to be raised thus rocking the bell-cranks 35, 36 clockwise, asviewed in Fig. 7 so that the bail 30 is moved towards the front of theribbon 1, engages the lower ends of arms 18, and swings the retractablescoring devices 17 out of engagement with the ribbon.

The switch 42 remains operated for a period longer than that duringwhich operation of the scoring devices 17 is to be interrupted and theinterval during which the devices 17 remain ineffective is determined byan adjustable abutment comprising a set-screw 68 in a block 69 slidablelengthwise of the piston rod 63. A biased trip member 70 rests on theset screw 68 and as the piston rises the member 70 is rocked about itspivot 71 until a pin 72 on the trip member engages the latch 51 androcks it clockwise, Fig. 7, about its pivot 50 until it is disengagedfrom the lever 53, as indicated in chain-lines, Fig. 7. Thespring-controlled plunger 55 is then released, thus cutting off thesupply of air under pressure to the cylinder 60 whereupon weights 73 and74 carried respectively by the piston rod 63 and the bell-crank 36 causethe piston to descend at a rate regulated by the regulator 61 and theair in the cylinder to be exhausted by the valve 56, through an exhaustpipe 75. As the piston descends, the trip member 70 automaticallyreturns to pristine position, the bell cranks 35, 36 and the bail 30 arealso gradually restored to their starting positions thus permitting thescoring devices 17 to reengage the ribbon 1. The mercury switch 42returns to its normal inoperative position when, under proper controlthe leading end portion of the ribbon is snapped off in known manneralong a score line T by means of the tilting sucker device 14, and theelectric circuit is then broken through the contactor 47 so that thesolenoid 48 is de-energised and the latch 51 reassumes a verticalposition, engaging the control lever 53.

The distance D, Fig. 2, between the adjacent ends of successivelongitudinal score lines may be about one inch.

It should, however, be so chosen that on each side of the transversescore line T is a distance not less than about one-quarter of an inchwide which is not weakened by longitudinal score lines. Adjustment ofthe distance D between the adjacent ends of successive longitudinalscore lines may, as desired, be obtained by adjusting the position ofthe abutment 68 on the piston rod 63.

When the leading end portion of the ribbon reaches a predeterminedposition it is, in known manner, as mentioned above, and under propercontrol, snapped off the ribbon along the transverse score line T.Theportion of ribbon as illustrated in Fig. 3, so removed is disposed ona portable frame or a table and then, again under proper control, themarginal portions E, Fig. 4, are snapped off along the lines L1, L3 andthe remaining portion is then snapped along line L2 to produce two glasssections S1, S2 in sheet form of predetermined dimensions.

I claim:

1. A method of producing glass sections in sheet form of predetermineddimensions from a moving ribbon of glass characterised by defining thewidth of the sections to be produced by forming longitudinal score linesin spaced relation on one face of the moving ribbon, forming transversescore lines on the other face of the ribbon to determine the length ofthe sections, interrupting each longitudinal score line for a shortdistance at such a distance from the leading edge of the ribbon that atransverse score line does not cross the longitudinal score lines anddoes not prematurely start division of the ribbon along the longitudinalscore lines when the ribbon is snapped along a transverse score line,and snapping the ribbon along a transverse score line and subsequentlyalong the longitudinal score lines to obtain the glass sections ofpredetermined size.

2. In apparatus for vertically drawing flat glass in ribbon formincluding means for scoring a line of breakage across the ribbonemerging from the annealing chamber of a drawing kiln at a predetermineddistance from the leading edge of the ribbon; retractable cutters forforming longitudinal score lines in spaced relation on the movingribbon, operatively associated with interrupting mechanism, saidinterrupting mechanism comprising a settable switch actuated by theleading edge of the ribbon, a spring controlled valve, actuating meansfor said valve and electrical means controlled by the said settableswitch for activating the said actuating means to move the valve to theopen position, a piston working in a cylinder supplied with motive fluidthrough said valve, means operatively associated with the piston andsaid actuating means for dissociating the actuating means for said valvefrom said valve to permit said valve to return to closed position, meansoperatively connecting said piston to the retractable cutters to movethem out of operative position upon admission of fluid to the cylinder,and means for returning the retractable cutters to operative positionand the piston and the dissociating means respectively to theinoperative position when the fluid is cutoff from the cylinder.

3. Apparatus according to claim 2 including means adjustably associatingthe dissociating means with the piston whereby the means fordissociating the actuating means for said valve is adjustable withrespect to the piston so that the period of dissociation may beregulated.

4. In apparatus for vertically drawing flat glass in ribbon formincluding means for scoring a line of breakage across the ribbonemerging from the annealing chamber of a drawing kiln at a predetermineddistance from the leading edge of the ribbon: retractable cutters forforming longitudinal score lines in spaced relation on the movingribbon, an interrupting mechanism operatively associated with saidretractable cutters, said interrupting mechanism comprising a settableswitch actuated by the leading edge of the ribbon, said settable switchcontrolling a circuit comprising a solenoid to which a verticallydisposed latch is hinged, whereby the latch is raised when the circuitis energised, a piston working in a cylinder, a spring controlled valvecontrolling supply of motive fluid to the cylinder, said valve beingnormally held in the closed position, a control lever connected with thevalve and engaged by the latch whereby the valve is moved to openposition when the latch is raised, a piston rod connected to the piston,means articulated to said rod for moving the retractable scoring meansout of the normal (operative) position when the switch is actuated, abiased trip supported for actuation by said piston rod and disposed inproximity to the latch so that in one direction of movement of the rodthe trip disengages the latch from the control lever and frees the valveto return to closed position for the fluid, said trip automaticallyregaining pristine position in the other direction of movement of thepiston rod; the arrangement being such that motive fluid is only passedto the piston cylinder when the latch rocks the control lever to movethe valve to the on position, achieved by the operation of the settableswitch, said latch being reset when the switch resets and de-energisesthe circuit.

5. Apparatus according to claim 4 including an abutment supported by thepiston rod for actuating the trip and means adjustably securing theabutment with respect to the piston rod, the period of admission ofmotive fluid being regulated by the setting of the abutment on thepiston rod.

6. Apparatus according to claim 4 wherein the means for moving theretractable scoring means comprises a biased bell crank operativelyconnected to the piston rod, a bail disposed transversely of the ribbonto engage the retractable scoring device and links connecting the bellcrank to the bail for retracting the scoring device when motive fluid isadmitted to the piston cylinder.

Williamson Apr. 19, 1932 Hinkle Oct. 21, 1.941

